Twin Turbo setup - How to know if one is jammed

[Dispatcher]

I was searching out this info, couldn't find any clues. What happens when one turbo on a twin setup, 1JZ or 1G-GTE fails,not spin etc.
What are the symptoms ? OR if the problems is just starting what are the signs to look for ?

Thanks
Dispatcher

[Blair]

Also keen to see some replies, tried to do a search but couldn't find much.

[Bananaman]

I would think that if one was completely jammed then you would notice a drastic loss in power... It would be very tough not to notice I imagine the odds of it completely seizing are pretty minimal anyway

More likely with these is oil seals going, which will show itself as smoke under power, or in my case a buildup of smoke at idle as well

[Blair]

Well my car doesn't seem all that powerful, but I don't know how well a 1ggte goes stock in an ra65. Might have to dyno it.

[Kedderz]

What gen is your 1g Blair, if stock and gen3 running stock boost with a stock dump pipe (restrictive) you will be around 120-130rwkw.

[lexsmaz]

The Maximum boost developed would be well down on normal levels & also the boost what there is would come on quite a bit later through the whole range as its only pumping half the volume of air..

But as has been mentioned i'm sure there would be other issues too ..

Kedders, do you think it could be that high ? i have seen some stocky 1JZ GTE's with not a real lot more than that ..

[Kedderz]

Check the 1ggte dyno thread mate, lots of stock dyno figures around that figure. Remember gen3's run 11psi.

With a set of dump pipes I was making 140rwkw on my 1ggte, stock boost + stock turbos.

[roadsailing]

I'm not a fan of thinking of symptoms to diagnose problems, but I would guess the working one would run hotter than the non working one.

You could try forcing open the wastegates one at a time and seeing if it makes any difference, or fitting a pressure tap before each turbo and seeing if they are pulling the same vacuum on boost.

Can you get the inlets off easily?

[wilbo666]

On 1JZ / 1G style twin turbo setups, where the turbos are in parallel and share a common intake if you have one turbo 'Jammed' then you will not make any significant boost.

All the air pressure that your working turbo tries to generate will go back out to atmosphere via the 'jammed' turbos compressor side as this is a much less restrictive path than going into the engine

Your working turbo won't be able to work as intended

I hope this makes sense for the full failure.

Cheers
Wilbo

[Muziiz]

Do you have boost pressure guage? If not then get one that way you know if its producing proper boost. Then go looking for problems. Are you hearing any noises ?

[midnight_purple_GA70]

On 1JZ / 1G style twin turbo setups, where the turbos are in parallel and share a common intake if you have one turbo 'Jammed' then you will not make any significant boost.

All the air pressure that your working turbo tries to generate will go back out to atmosphere via the 'jammed' turbos compressor side as this is a much less restrictive path than going into the engine

Your working turbo won't be able to work as intended

I hope this makes sense for the full failure.

Cheers
Wilbo

this man speaks the truth... my rear turbo of a 1jz had a snapped shaft and the rear wheel was lodged into the rear housing of the turbo... strange thing was from the front wheel it felt quite normal and spun freely etc... also didnt blow any smoke etc

the result was no boost and the car struggled to build revs as there was a major restriction in the exhaust housing ie the non spinning turbo wheel...

[Dispatcher]

Thank you all very much, I will keep this info handy.

My 1JZ is still making decent boost. But there's some whistling (or whining) that comes on on start and sometimes on acceleration.


Cheers
Dom

[Muziiz]

Thank you all very much, I will keep this info handy.

My 1JZ is still making decent boost. But there's some whistling (or whining) that comes on on start and sometimes on acceleration.


Cheers
Dom

It could be loose intercooler hose. Worse case turbos wearing out

[Blair]

mines a gen2 1ggte.

I also get that whining/whistle sometimes when coming on boost.

[Kedderz]

Gen2 will be around 100kw at the wheels, stock boost.